An example of a conventional scroll compressor includes an orbiting scroll having a scroll wrap formed on a surface of a base plate, a frame that axially supports the orbiting scroll, a pair of Oldham keyways formed in the orbiting scroll, a pair of Oldham keyways formed in the frame in the direction perpendicular to the keyways of the orbiting scroll, and an Oldham ring placed between the orbiting scroll and the frame (see, for example, Patent Literature 1).
A pair of Oldham keys that slidably engage with the Oldham keyways of the orbiting scroll or frame and projections (protrusions) are formed on both surfaces of this Oldham ring. During operation of the scroll compressor, the orbiting scroll and the frame slide on the Oldham ring. The projections (protrusions) enable the contact area thereof, and hence friction due to the sliding, to be reduced.